What’s New in the Patient Safety World

March 2012

How Dangerous is a Day in the Hospital?



How dangerous is a day in the hospital? For many years, we have used the numbers from a study done by Lori Andrews et al. (Andrews 1997) that found you have a 6% chance per inpatient day of having an adverse event. And, of course, a 2010 report (Levinson 2010) showed that one in every seven Medicare patients who is hospitalized experienced adverse events during their hospital stays, up to 44% being potentially preventable.


A new study (Hauck 2011) tries to quantifty the risk even further. Using a large database from public hospitals in Australia, the authors calculated that the average hospital stay carries a:

·        5.5% risk of adverse drug reaction

·        17.6% risk of infection

·        3.1% risk of pressure ulcers


Moreover, each additional night in the hospital increases the risk by 0.5% for adverse drug reactions, 1.6% for infections, and 0.5% for pressure ulcers.


They used a complex set of equations to do these calculations and did adjust for such variables as age, sex, whether the patient died, whether the patient was admitted emergently, and complexity (as measured via the Charlson index). They also adjusted for outliers with respect to LOS.


Interesting. Our grandparents always regarded hospitals as dangerous places. They had no idea what the statistics were!







Andrews LB, Stocking C, Krizek T, et al. An alternative strategy for studying adverse events in medical care. Lancet 1997; 349: 309–313




Levinson DR. Adverse Events in Hospitals: National Incidence Among Medicare Beneficiaries. Washington, DC: US Department of Health and Human Services, Office of the Inspector General; November 2010. Report No. OEI-06-09-00090




Hauck K, Zhao X. How Dangerous is a Day in Hospital?: A Model of Adverse Events and Length of Stay for Medical Inpatients. Medical Care 2011; 49(12): 1068-1075, December 2011



















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